@Vivian said in I want to survey a drone with 5G enable and have some questions:

XL2 use the same structure and OS? and from your

Hi Vivian,

Sorry for the slow reply. VOXL 2 uses the same chipset, operating system and SDK (VOXL SDK) as the Qualcomm Flight RB5. The VOXL 2 is a smaller and lighter footprint than the core components of the RB5 Flight, but it does not have built-in WiFi. Please check out https://docs.modalai.com/voxl2-d0006/ as a reference for an architecture with VOXL 2. Check out the developer bootcamp for details on how to get started

@QSL Hi, thank you for reaching out. There are many ways to achieve what you are trying. Starling 2 is the best starting point. You can then learn about what will work and what will not work and build out your system design from there.

Hi @Alex-Kushleyev , @QSL 170-250mm is quite long. I'm not optimistic 250mm can even work, 170 would be risky.
We can offer our design services, but typically what that results in is a MOQ of a specific new item, such as 300-500pcs depending on the complexity (at normal MRSP which for flexes runs ~$50-80 each) and lead times would be ~14-18 weeks.
What we would need is a .dxf outline of your intended design and we can review that for feasibility and interest. If it really is 250mm, I'd prefer to no-bid it. 200mm might be the edge here (we do not have sophisticated Sigrity tools to confirm, so going on experience here).
M0170 is not ideally suited for back-to-back (the connectors are a bit offset from each other so the net result would be weird) but it may prove if 140mm can work + ~10 mm for the connector transition losses.
In situations like this, I encourage the ME/Industrial Design Team to reconsider placement of sensors and main electronics relative to each other. There are just some constraints the electronics cannot meet easily. Sometimes just simply re-prioritizing the system constraints helps solve the spatial/distance problems. To extend past ~180+mm, I would encourage you use an external design firm that knows how to do mipi repeaters and high speed design. We've had one customer successfully do that, but it takes some skill and we could do it ourselves, but we just do not have the design cycles to support it this calendar year.
Hope this helps and let us know what your thoughts are, and if pursuing us for a custom design is an option, we can reach out over email.

@mkeyno You need to work with the PX4 community on this project, not ModalAI.

Hi @Eyal ,

I just did a quick test and I am getting 2.0ms ping time when voxl2 cpu is in perf mode, and about 2.5ms when in auto mode. VOXL2 is idle.

the NCM networking feature works concurrently with ADB, which is great and we also have some scripts to set up NAT if you need your voxl2 to actually use the Linux host as a "router" to access outside world. that is easy to set up as well (requires some routing changes on the linux host).

In terms of real-time streaming, it is definitely adequate for image / video streaming to a Linux host. In fact, this option is my personal favorite way of connecting to Voxl2 while developing / testing cameras and viewing multiple streams in voxl-portal. Voxl-portal uses jpeg compression, which is a lot less efficient than h264/h265 and with the NCM connection, i don't have any issues (compared to adb port forwarding, which also allows voxl-portal to work, but is about 10x slower and uses a lot more CPU, you get frame drops in voxl-portal if required bandwidth is higher than 30-50Mbps or so). I am mainly using the USB-NCM feature for development purposes (as opposed to on a flying drone), but i have not found any limitations, at least for the bench testing use case.

In terms of CPU load affecting the speed, i just ran a test stress -c 8 which loads up all 8 cores to 100% and the ping times did not change in perf mode (2.0ms) and in auto mode, the ping times reduced from 2.5ms to 2.0ms because the cpu cores are actually running at faster speeds. I am guessing that all the USB stuff is happening in the kernel at a higher priority, so it's not affected by the user applications (unless the cpu overheats, i supposed). GPU / DSP loads should not have any effect on this, since they are separate hardware.

I also did another test - stream 4 video streams to voxl-portal (live view), which added up to about 100Mbps of network traffic and ping time stayed between 1.5-3.0ms (sometimes lower than 2.0ms).

I have not observed any stability issues related to NCM being active for long periods of time (days). Make sure you are using a high quality USB-C cable (nothing fancy).

Alex